Moderate shading can mitigate the negative impacts on the growth of tea plant and quality components caused by nitrogen reduction in northern tea plantations

Excessive use of chemical fertilizers leads to environmental pollution and a decline in tea quality. To promote sustainable development while maintaining high-quality productivity, reducing nitrogen fertilizer application is an effective strategy for cost savings and emission reduction in tea plantations. However, there is a lack of integration and testing with other efficiency-enhancing measures. This study explores the potential of moderate shading to mitigate the negative effects of reduced nitrogen fertilizer on the growth and quality of clonal tea plant. Focusing on the local variety 'Shaancha 1', this study uses field experiments to evaluate the growth and quality components of tea plant under different combinations of nitrogen fertilizer concentrations (0, 90, 180, 360 kg N ha⁻¹) and shading treatments, which include varying shading durations (0, 7, 38 d) and intensities (0%, 40%, 70%). Results showed that, compared to the traditional high-nitrogen fertilization regime, applying 180 kg N ha⁻¹ combined with a short-term shading duration of 7 d and 40% shading intensity promoted tea plant growth by enhancing antioxidant capacity. This treatment also ensured tea yield and improved the content of several quality components. The combination of low-level shading and reduced nitrogen fertilizer application is an empirical case that enhances tea yield and quality. It provides practical measures for eco-friendly tea cultivation while also helping to lower costs and emissions.